Draft yoke



March 13, 1934. s ows 1,951,318

DRAFT YOKE Filed May 5, 1928 2 Sheets-Sheet l Illlll March 13, 1934. D. s. BARROWS DRAFT rom Filed May 5, 1928 2 Sheets-Sheet 2 mmlmm 0000/0 J fiarrams Patented Mar. 13, 1934 ire s'rars AT :51; N GFFKYE DRAFT YOKE Application May 5, 1928, Serial No. 275,501

4 Claims.

This invention relates to draft yokes for railway cars and more particularly to a form of cast horizontal yoke designed for substantially uniform fiber stress in the various sections thereof.

The principal object of my invention, generally considered, is to produce a yoke well-suited to be manufactured from cast steel and which is relatively light in weight for its strength on account of being designed for substantially uniform fiber stress in the various sections thereof,

the front ends of the slotted portions of saidyoke being reinforced for increasing the bearing area for the associated front key.

Another object of my invention is to provide a cast steel horizontal yoke in which the width or height of the arms forwardly of the connecting portions between the rear ends of said arms is maintained the same as the corresponding dimension of said connecting portions to the slotted portions of said arms, the fiber stress being maintained substantially uniform by decreasing the thickness of said arms.

A further object of my invention to provide a horizontal cast steel yoke in which the rear end corners or the junctions between the rear ends of the yoke arms and the connecting portion between said arms are strengthened by triangular reinforcements on the outside of said corners, said reinforcements preferably extending forwardly along the arms and tapering to gradually merge in to the outer surfaces thereof.

A still further object of my invention is to provide a cast steel horizontal yoke in which the arms thereof are normally five-sided in section rearwardly of the slotted forward portions thereof, said section being spread at the slotted portions to a six-sided section by spacing the upper and lower portions of said substantially double trapezoidal section by a rectangular mid-section, said rectangular mid-section approximately corresponding in dimensions with the depth or width of the slots.

An additional object of my invention is to provide a cast steel horizontal yoke in which the fiber stress is more nearly uniform by providing for the maximum section of metal at the corners or junctions between the rear ends of the yoke arms and the connecting member therebetween and forming the front ends of said yoke arms substantially semi-elliptical in side elevational outline.

Other objects and advantages of the invention relating to the particular arrangement and construction of the various parts will become appar-- ent as the description proceeds.

Referring to the drawings illustrating my invention, the scope whereof is defined by the appended claims,-

Figure 1 is a plan of a form of yoke embodying my invention.

Figure 2 is a side elevational view of the yoke illustrated in Figure 1.

Figure 3 is a fragmentary elevational view of the front portion of the yoke shown in Figure 2, with the reinforcement around the front end of the slotted portion slightly modified.

Figure 4 is an end elevational view of the front end of the arm of the yoke shown in Figure 2.

Figure 5 is a vertical sectional view on the line 5-5 of Figure 1, looking in the direction of the arrows.

Figure 6 is a fragmentary View corresponding to Figure 3, but showing another modification.

Figure 7 is a fragmentary View of a corner of a yoke such as shown in Figure 1, but showing a modification.

Figure 8 is a sectional view on the line 8-8 of Figure '7.

Figure 9 is a view corresponding to Figure 1, but showing another modification.

Figure 10 is a side elevation of the form of yoke shown in Figure 9.

Figure 11 is a sectional view on the line 11-11 of Figure 10, looking in the direction of the arrows.

Figure 12 is a sectional view on the line 12 12 of Figure 10, looking in the direction of the arrows.

Figure 13 is a sectional View on the line 13- 13 of Figure 9, looking in the direction of the arrows.

Before considering the embodiments of my invention illustrated, it might be well to take up the development of yokes, such as shown in the drawings. The simplest form of a yoke of the horizontal type, such as is here disclosed, is one U-shape in plan and of uniform section throughout. It will be understood that the rear end of the yoke is subjected to greater strains than the forwardly extending arms thereof, and therefore, the simplest Way of increasing the section modulus of said rear end is to mereli widen or increase the depth of the material therein, without changing the thickness. This scheme is not as desirable as the method disclosed in the present application, because the standard yoke filler is notched for a 5 yoke a d. herefore it is preferable to keep the depth or thickness of the metal in the yoke at the rear end thereof at 5 Another way of increasing the strength at the rear end of the yoke is to increase the thickness, not only of said rear end but of the rear portion of the arms of said yoke, leaving the corners square, whereby maximum cross-sectional area is formed at said corners which are critical points in the yoke.

For maintaining substantially uniform unit stress in the metal of the yoke, the cross sectional area between the back or rear ends of the second slots and the reinforcements of the rear corners of the yoke may be reduced. This can be done by maintaining the normal l thickness of the metal and decreasing the normal 5 width or depth of the yoke but the width or depth is preferably maintained 5 and the thickness decreased to approximately 1 Instead of reinforcing the corners by leaving them square, a preferable reinforcement for a cast yoke involves the formation of the section at' the corners five-sided, that is, with a triangular extension or reinforcement on the outer side thereof, the outer surface of said reinforcement, instead of being sharp angled, curving around the corners as shown in the drawings, thereby avoiding casting difficulties as will be understood. The strength of the yoke at the rear corners or junctions between the rear ends of the arms and the connecting portion may be increased by interior or exterior ribbing, giving a configuration preferably U, double U or T- shape in cross section. This, however, takes up morcrcom than the preferred forms of the invention to be described in detail hereinafter, and as a draft yoke is used in combination with cushioning mechanism, between said mechanism and the associated draft sills there is very little space for ribbing which increases the overall thickness of the yoke arms.

Referring now to the drawings in detail, like parts being designated by like reference characters, and first considering the embodiment of my invention illustrated in Figures 1, 2, 4 and 5, a draft yoke l of the horizontal type is illustrated, formed generally U-shaped in plan and comprising spaced preferably parallel arms 2 and a connecting tie 3 by which the arms are integrally united at their rear ends. The arms 2, which are adapted to receive the draft gear or cushioning mechanism therebetween, are preferably provided adjacent their forward ends with aligned slots 4 for receiving a key adapted to connect the associated car coupler to the yoke in a well-known manner. The arms 2 may also be formed with additional oppositely disposed key slots 5 for the purpose of receiving a key adapted to pass through a slotted front follower block (not shown), employed in the well-known form of draft rigging commonly called Farlow two-key draft rigging.

To preserve the strength of the yoke adjacent the slots 4, as well as in the neighborhood of the slots 5, when the yoke arms are provided with such slots, the said arms are of greater width adjacent said slots than their rear portions 6 lying between the slots 5 and the connecting portion 3. For the purpose of providing great strength in the yoke arms at their junctions with the transverse tie 3, said junctions are preferably strengthened by triangular reinforcements or bulges 7 on the outside of the corners or junctions between the arms and tie member 3. The outer surface of the reinforcements 7 is preferably curved around the corners and slopes upwardly and downwardly from the horizontal mid-section of the yoke to merge with the normal thickness of material, as illustrated.

It will be understood that the tie member 3 is subjected to greater strains than the arms 2 of the yoke and therefore is preferably thicker, the preferred thickness being 1 This thickness is preferably extended around the corners, which are reinforced at 7 and continued forwardly to gradually merge into the portions 6 of the yoke, which are preferably of decreased thickness, say 1 the height or width of the yoke being maintained at 5 to correspond with standard yoke fillers, which are notched for a 5 /2" yoke and also to correspond with existing yoke carriers, which are spaced 2% below the center line of draft.

Adjacent the rear ends of the slots the thickness of the yoke arms is preferably increased to 1- 1" in order to avoid the necessity for greatly increasing the depth or width of the arms to compensate for the key slots 4 and 5 therein.

If 1% slots are employed the metal above and below each slot, being preferably 2 /2, a total height or width at the slotted portions of the yoke of 6%" is provided, the net section through the slots corresponding approximately with the section between the rear ends of the slots and the front ends of the corner reinforcing portions.

In order to increase the bearing area for the front key (not shown) on the front ends of the slotted portions 4 in the yoke for the effective transfer of draft forces from said key to the yoke without undue strain in the metal, inner and outer reinforcements 8 are preferably provided, which are of maximum strength directly around the front edge of the slots 4 and taper forwardly to merge into the side walls of the arms at the extreme front end of said arms, said reinforcement also tapering rearwardly into the sides of said arms, as illustrated. The forward taper is preferably, not only transversely of the arms, but also vertical, so that the reinforcement is substantially arrow-headed in outline as illustrated particularly in Figure 2.

The contour of the free or front ends of the yoke arms 2 is curved to be preferably not entirely circular but approximately semi-elliptical, as indicated particularly at 9 with the long axis extending longitudinally of the yoke. The reinforcement on the inner surface of the yoke arms preferably not only merges into the normal plane of the inner surface at the front ends of the arms but extends beyond said surface, forming a cut-away portion, as indicated at 10, thereby allowing for angling between the coupler and yoke and facilitating insertion of 1-35 the coupler stem between the arms of the yoke.

Referring now to the embodiment of my invention illustrated in Figure 3, a slightly modi fied form of front end reinforcement 8 is illustrated, which reinforcement covers approxireinforcement corresponding to that illustrated V in Figure pt that the width of the maxi- M) mum reinforcement, designated particularly at 11, is substantially increased and from said maximum reinforcement, the thickness tapers to merge into the normal thickness of the yoke arms at the extreme edge or outline thereof.

In the form of yok illustrated in Figures 1, 2, 4 and 5, the parting line of the patternand mold is midway of the section. It is sometimes advantageous to mold the yoke with the parting line of the mold arranged at the upper face rather than intermediate the upper and lower faces and such necessitates a section in which the greatest thickness is not midway between the upper and lower faces. Such a modified form is illustrated in Figures 7 and S, in which the section at the reinforced corners 7 of the yoke 1 is approximately rectangular, as indicated in Figure 8, rather than being five-sided, as indicated in Figure 5, the necessary draft, of course, being provided for removing the pattern from the mold. Otherwise, the yoke 1 may correspond in configuration with the yoke 1, except that the reinforcement at the front ends of the forward slots would be correspondingly modified or omitted, or the parting line need not be at the top edge of the pattern and mold along the full length of the yoke.

Referring now to the modification of my invention illustrated in Figures 9 to 13, inclusive, a yoke 1 is there shown which is identical with the yoke 1 of Figures 1, 2, 4 and 5, except that the normal section of the arms 2 at the portion 6 thereof is five-sided, as indicated in Figure 12, that is, the outer surface instead of being a vertical plane surface slopes both ways from the mid-point upwardly and downwardly slightly toward the corresponding inner surface. Where the slots 4 and 5 are provided in the arms 2 of the yoke, the five-sided section is preferably spread to one with six sides, by spacing the tapering upper and lower sections by a rectangular mid-section, approximately corresponding with the width of the slots, as illustrated in Figure 11. The rear end or connecting portion 3 of the yoke may correspond with that of the first embodiment, the reinforcing portion 7 however, being slightly modified in that instead of having a line of maximum reinforcement midway between the upper and lower edges of the yoke, a band, or area 12 of maximum reinforcement is provided, the reinforcement tapering both ways from said band to merge into the normal section of the yoke, as illustrated. It will be understood, however, that the reinforcement '7 may be identical with the reinforcement 7 of the first embod'ment, if desired. The reinforcement 8 at the front ends of the slots 4 corresponds with the reinforcement 8, illustrated in Figures 1, 2 and 4 but it will be understood that the reinforcing may correspond with that shown in Figures 3 or 6, if desired. It will be understood that the corners of the yoke 1 may be reinforced, as indicated in Figures 7 and 8, if desired.

From the foregoing disclosure, it will be apparent that I have devised a yoke which is admirably adapted for being formed of cast steel and in which the width of the arms rearwardly of the slotted portions is maintained to correspond with the width of the connecting or backstop engaging portion of the yoke, the thickness of said arms being decreased to equalize the fiber stress in the metal. The rear end corners of the yoke are preferably strengthened by triangular or tapering reinforcements which merge into the normal side surfaces of the yoke at the top and bottom edges thereof and taper and extend forwar ly to merge with the normal side surfaces of the arms of said yoke, preferably about 5" fromthe rear end of said yoke. In the embodiment shown in Figures 9 to 13, in clusive, the triangular reinforcement is continued forwardly at reduced thickness, spread around the slots and finally merged or blended with the front end reinforcements. Ihis results in the spreading of a normally five-sided section to a six-sided or double trapezoidal form, spaced by a rectangular mid-section through the slots. Although the front ends of the arms of the yoke may be curved as circles around the front ends of the front slots in. said arms, they are preferably elongated or formed substantially semi-elliptical as illustrated for equalizing the fiber stress. In all of the forms shown, it is planned to provide a maximum section of metal at the corners of the yoke or at the junctions between the rear ends of the arms thereof and the transverse connecting portion is adapted to engage a draft rigging backstop at its rear side and an associated draft gear cushioning mechanism or filler block at its front face. Although some of the preferred dimensions have been specified, it is to be understood that they are merely illustrative and not limiting.

Having thus described my invention, I claim:

1. A draft yoke comprising spaced arms connected at their rear ends and adapted to receive a cushioning unit therebetween, the forward portions of said arms being slotted for connection with an associated car coupler, the connecting portion being adapted to engage an associated draft rigging backstop, the corners of said yoke between said connecting portion and the rear ends of said arms being strengthened by reinforcements tapering in depth and width on the outer surfaces thereof, curved horizontally around the corners and merging at their ends into the outer surfaces of the yoke.

2. A draft yoke comprising spaced arms connected at their rear ends and adapted to receive a cushioning unit therebetween, the forward portions of said arms being slotted for connection with an associated car coupler, the connecting portion being adapted to engage an associated draft rigging backstop, the corners of said yoke between said connecting portion and the rear ends of said arms being strengthened by reinforcements substantially triangular in section on the outer surfaces thereof, said reinforcements extending forwardly along the outer surfaces of said arms and tapering horizontally and vertically in opposite directions from the corners to merge with the arms and rear connection.

3. A draft yoke comprising spaced arms connected at their rear ends and adapted to receive a cushioning unit therebetween, the forward portions of said arms being slotted for connection with an associated car coupler, the connesting portion being adapted to engage an asscciated draft rigging backstop, said arms being generally five-sided in section with the outer surfaces sloping from approximately the mid- 1;

section upwardly and downwardly toward the inner surfaces, said section at the slotted portions being of increased width to form a sixsided figuie and including a rectangular mid portion approximately corresponding with the point forward of said ends to a point rearwardly thereof from whence they taper to gradually merge into the sides of the arms, and said arms to the rear of said slots being generally fivesided in section, to blend easily with said reinforcements, with the outer surfaces sloping from approximately the mid-section toward the edges and inner surfaces, said arms at the slotted portions being widened to a six-sided section by spacing tapering edge sections by a portion rectangular in section and approximately corresponding in width with that of the slots.

DONALD S. BARROWS. 

